1. Field of the Invention
The present invention relates to a vehicle air conditioner which controls a temperature and an amount of conditioned air to be blown into a passenger compartment in accordance with an environmental condition of the vehicle, such as a solar radiation amount and a solar radiation direction.
2. Description of Related Art
In a conventional vehicle air conditioner, a temperature, an amount and the like of conditioned air to be blown into a passenger compartment are controlled in accordance with predetermined control characteristics, based on an environmental condition such as detection values of an outside air temperature sensor, an inside air temperature sensor and a solar radiation sensor. For example, in a vehicle air conditioner disclosed in JP-A-64-43847, a control unit performs a learning air-conditioning control by changing the control characteristics for every user.
In the vehicle air conditioner having a learning air-conditioning control, the control characteristics are changed based on an air-conditioning setting state manually set by a passenger. Specifically, when an air temperature is manually changed by the passenger in an air-conditioning control performed based on the predetermined control characteristics, it is determined that the predetermined control characteristics do not reflect the passenger's preference. In this case, the control characteristics are changed based on the manually set state.
However, even when a solar radiation amount detected by the solar radiation sensor does not change, if a solar radiation condition such as a solar radiation direction changes, thermal feeling of the passenger is changed. Therefore, in this case, uncomfortable feeling is sometimes given to the passenger. Especially, in the vehicle air conditioner having the learning air-conditioning control, if the change of the solar radiation direction frequently occurs, manual operation is required to be frequently performed in order to remove the uncomfortable feeling, regardless of the operation of the learning air-conditioning control. For example, when a direction of solar radiation radiated to a passenger on a driver seat frequently changes, the manual operation is required to be frequently performed.